在MailMessage中添加附件base64图像并在html正文中读取它

Question

目前,我有发送电子邮件与MailMessage和SmtpClient,但我需要发送图片当前在base64 string该范围内MailAddress的身体.

我已经认识到有必要把它的Attachment,但我不知道如何把base64在MailMessage类,然后,以可视化的电子邮件的正文中的图像阅读.我没有网址图片路径.

Answer 1

要嵌入图像到您的邮件:(它不一样添加附件文件消息)

如果您使用system.net.mail命名空间发送邮件,则无需将映像转换为base64.

var mail = new MailMessage();
var imageToInline = new LinkedResource("Your image full path", MediaTypeNames.Image.Jpeg);
            imageToInline.ContentId = "MyImage";
            alternateView.LinkedResources.Add(imageToInline);
mail.AlternateViews.Add(body);

更新:

这种将图像嵌入到mailMessage中的方式有​​点笨拙.

Byte[] bitmapData = Convert.FromBase64String(FixBase64ForImage("Your base64 image string"));
System.IO.MemoryStream streamBitmap = new System.IO.MemoryStream(bitmapData);

public static string FixBase64ForImage(string Image)
{
        System.Text.StringBuilder sbText = new System.Text.StringBuilder(Image, Image.Length);
        sbText.Replace("\r\n", string.Empty); sbText.Replace(" ", string.Empty);
        return sbText.ToString();
}


var mail = new MailMessage();
var imageToInline = new LinkedResource(streamBitmap , MediaTypeNames.Image.Jpeg);
imageToInline.ContentId = "MyImage";
alternateView.LinkedResources.Add(imageToInline);
mail.AlternateViews.Add(body);

你的html邮件正文应该有以下标记:

 <img alt ="" src ="cid:MyImage"/>

Answer 2

将正文HTML转换为AlternateView的完整方法

bodyHtml示例：

<p>example</p>
<p><img src=\ "data:image/jpeg;base64,---base64string---"></p>
<p>example</p>
<p><img src=\ "data:image/png;base64,---base64string---"></p>
<p>something</p>

使用此方法，您可以通过许多ESP（gmail，Outlook等）可视化多个图像。

private static AlternateView ContentToAlternateView(string content)
    {
        var imgCount = 0;
        List<LinkedResource> resourceCollection = new List<LinkedResource>();
        foreach (Match m in Regex.Matches(content, "<img(?<value>.*?)>"))
        {
            imgCount++;
            var imgContent = m.Groups["value"].Value;
            string type = Regex.Match(imgContent, ":(?<type>.*?);base64,").Groups["type"].Value;
            string base64 = Regex.Match(imgContent, "base64,(?<base64>.*?)\"").Groups["base64"].Value;
            if (String.IsNullOrEmpty(type) || String.IsNullOrEmpty(base64))
            {
                //ignore replacement when match normal <img> tag
                continue;
            }
            var replacement = " src=\"cid:" + imgCount + "\"";
            content = content.Replace(imgContent, replacement);
            var tempResource = new LinkedResource(Base64ToImageStream(base64), new ContentType(type))
            {
                ContentId = imgCount.ToString()
            };
            resourceCollection.Add(tempResource);
        }

        AlternateView alternateView = AlternateView.CreateAlternateViewFromString(content, null, MediaTypeNames.Text.Html);
        foreach (var item in resourceCollection)
        {
            alternateView.LinkedResources.Add(item);
        }

        return alternateView;
    }

将Base64转换为流：

public static Stream Base64ToImageStream(string base64String)
    {
        byte[] imageBytes = Convert.FromBase64String(base64String);
        MemoryStream ms = new MemoryStream(imageBytes, 0, imageBytes.Length);
        return ms;
    }

设置MailMessage：

MailMessage mail = new MailMessage();
mail.IsBodyHtml = true;                   
AlternateView alterView = ContentToAlternateView(bodyHtml);
mail.AlternateViews.Add(alterView);
//more settings
//...
//////////////
SmtpClient smtp = new SmtpClient(Host, Port) { EnableSsl = false };
smtp.Send(mail);